1 // SPDX-License-Identifier: GPL-2.0-only
9  * This allocator returns small blocks of a given size which are DMA-able by
10  * the given device.  It uses the dma_alloc_coherent page allocator to get
11  * new pages, then splits them up into blocks of the required size.
15  * represented by the 'struct dma_pool' which keeps a doubly-linked list of
16  * allocated pages.  Each page in the page_list is split into blocks of at
17  * least 'size' bytes.  Free blocks are tracked in an unsorted singly-linked
19  * keep a count of how many are currently allocated from each page.
23 #include <linux/dma-mapping.h>
56 	unsigned int size;  member
75 	unsigned size;  in pools_show()  local
77 	size = sysfs_emit(buf, "poolinfo - 0.1\n");  in pools_show()
80 	list_for_each_entry(pool, &dev->dma_pools, pools) {  in pools_show()
81 		/* per-pool info, no real statistics yet */  in pools_show()
82 		size += sysfs_emit_at(buf, size, "%-16s %4zu %4zu %4u %2zu\n",  in pools_show()
83 				      pool->name, pool->nr_active,  in pools_show()
84 				      pool->nr_blocks, pool->size,  in pools_show()
85 				      pool->nr_pages);  in pools_show()
89 	return size;  in pools_show()
101 	for (i = sizeof(struct dma_block); i < pool->size; i++) {  in pool_check_block()
104 		dev_err(pool->dev, "%s %s, %p (corrupted)\n", __func__,  in pool_check_block()
105 			pool->name, block);  in pool_check_block()
112 				data, pool->size, 1);  in pool_check_block()
117 		memset(block, POOL_POISON_ALLOCATED, pool->size);  in pool_check_block()
122 	struct dma_page *page;  in pool_find_page()  local
124 	list_for_each_entry(page, &pool->page_list, page_list) {  in pool_find_page()
125 		if (dma < page->dma)  in pool_find_page()
127 		if ((dma - page->dma) < pool->allocation)  in pool_find_page()
128 			return page;  in pool_find_page()
135 	struct dma_block *block = pool->next_block;  in pool_block_err()
136 	struct dma_page *page;  in pool_block_err()  local
138 	page = pool_find_page(pool, dma);  in pool_block_err()
139 	if (!page) {  in pool_block_err()
140 		dev_err(pool->dev, "%s %s, %p/%pad (bad dma)\n",  in pool_block_err()
141 			__func__, pool->name, vaddr, &dma);  in pool_block_err()
147 			block = block->next_block;  in pool_block_err()
150 		dev_err(pool->dev, "%s %s, dma %pad already free\n",  in pool_block_err()
151 			__func__, pool->name, &dma);  in pool_block_err()
155 	memset(vaddr, POOL_POISON_FREED, pool->size);  in pool_block_err()
159 static void pool_init_page(struct dma_pool *pool, struct dma_page *page)  in pool_init_page()  argument
161 	memset(page->vaddr, POOL_POISON_FREED, pool->allocation);  in pool_init_page()
172 		memset(vaddr, 0, pool->size);  in pool_block_err()
176 static void pool_init_page(struct dma_pool *pool, struct dma_page *page)  in pool_init_page()  argument
183 	struct dma_block *block = pool->next_block;  in pool_block_pop()
186 		pool->next_block = block->next_block;  in pool_block_pop()
187 		pool->nr_active++;  in pool_block_pop()
195 	block->dma = dma;  in pool_block_push()
196 	block->next_block = pool->next_block;  in pool_block_push()
197 	pool->next_block = block;  in pool_block_push()
202  * dma_pool_create - Creates a pool of consistent memory blocks, for dma.
205  * @size: size of the blocks in this pool.
213  * cache flushing primitives.  The actual size of blocks allocated may be
217  * cross that size boundary.  This is useful for devices which have
225 				 size_t size, size_t align, size_t boundary)  in dma_pool_create()  argument
236 	else if (align & (align - 1))  in dma_pool_create()
239 	if (size == 0 || size > INT_MAX)  in dma_pool_create()
241 	if (size < sizeof(struct dma_block))  in dma_pool_create()
242 		size = sizeof(struct dma_block);  in dma_pool_create()
244 	size = ALIGN(size, align);  in dma_pool_create()
245 	allocation = max_t(size_t, size, PAGE_SIZE);  in dma_pool_create()
249 	else if ((boundary < size) || (boundary & (boundary - 1)))  in dma_pool_create()
258 	strscpy(retval->name, name, sizeof(retval->name));  in dma_pool_create()
260 	retval->dev = dev;  in dma_pool_create()
262 	INIT_LIST_HEAD(&retval->page_list);  in dma_pool_create()
263 	spin_lock_init(&retval->lock);  in dma_pool_create()
264 	retval->size = size;  in dma_pool_create()
265 	retval->boundary = boundary;  in dma_pool_create()
266 	retval->allocation = allocation;  in dma_pool_create()
267 	INIT_LIST_HEAD(&retval->pools);  in dma_pool_create()
270 	 * pools_lock ensures that the ->dma_pools list does not get corrupted.  in dma_pool_create()
279 	empty = list_empty(&dev->dma_pools);  in dma_pool_create()
280 	list_add(&retval->pools, &dev->dma_pools);  in dma_pool_create()
288 			list_del(&retval->pools);  in dma_pool_create()
300 static void pool_initialise_page(struct dma_pool *pool, struct dma_page *page)  in pool_initialise_page()  argument
302 	unsigned int next_boundary = pool->boundary, offset = 0;  in pool_initialise_page()
305 	pool_init_page(pool, page);  in pool_initialise_page()
306 	while (offset + pool->size <= pool->allocation) {  in pool_initialise_page()
307 		if (offset + pool->size > next_boundary) {  in pool_initialise_page()
309 			next_boundary += pool->boundary;  in pool_initialise_page()
313 		block = page->vaddr + offset;  in pool_initialise_page()
314 		block->dma = page->dma + offset;  in pool_initialise_page()
315 		block->next_block = NULL;  in pool_initialise_page()
318 			last->next_block = block;  in pool_initialise_page()
323 		offset += pool->size;  in pool_initialise_page()
324 		pool->nr_blocks++;  in pool_initialise_page()
327 	last->next_block = pool->next_block;  in pool_initialise_page()
328 	pool->next_block = first;  in pool_initialise_page()
330 	list_add(&page->page_list, &pool->page_list);  in pool_initialise_page()
331 	pool->nr_pages++;  in pool_initialise_page()
336 	struct dma_page *page;  in pool_alloc_page()  local
338 	page = kmalloc(sizeof(*page), mem_flags);  in pool_alloc_page()
339 	if (!page)  in pool_alloc_page()
342 	page->vaddr = dma_alloc_coherent(pool->dev, pool->allocation,  in pool_alloc_page()
343 					 &page->dma, mem_flags);  in pool_alloc_page()
344 	if (!page->vaddr) {  in pool_alloc_page()
345 		kfree(page);  in pool_alloc_page()
349 	return page;  in pool_alloc_page()
353  * dma_pool_destroy - destroys a pool of dma memory blocks.
362 	struct dma_page *page, *tmp;  in dma_pool_destroy()  local
370 	list_del(&pool->pools);  in dma_pool_destroy()
371 	empty = list_empty(&pool->dev->dma_pools);  in dma_pool_destroy()
374 		device_remove_file(pool->dev, &dev_attr_pools);  in dma_pool_destroy()
377 	if (pool->nr_active) {  in dma_pool_destroy()
378 		dev_err(pool->dev, "%s %s busy\n", __func__, pool->name);  in dma_pool_destroy()
382 	list_for_each_entry_safe(page, tmp, &pool->page_list, page_list) {  in dma_pool_destroy()
384 			dma_free_coherent(pool->dev, pool->allocation,  in dma_pool_destroy()
385 					  page->vaddr, page->dma);  in dma_pool_destroy()
386 		list_del(&page->page_list);  in dma_pool_destroy()
387 		kfree(page);  in dma_pool_destroy()
395  * dma_pool_alloc - get a block of consistent memory
408 	struct dma_page *page;  in dma_pool_alloc()  local
413 	spin_lock_irqsave(&pool->lock, flags);  in dma_pool_alloc()
418 		 * &pool->lock  in dma_pool_alloc()
420 		spin_unlock_irqrestore(&pool->lock, flags);  in dma_pool_alloc()
422 		page = pool_alloc_page(pool, mem_flags & (~__GFP_ZERO));  in dma_pool_alloc()
423 		if (!page)  in dma_pool_alloc()
426 		spin_lock_irqsave(&pool->lock, flags);  in dma_pool_alloc()
427 		pool_initialise_page(pool, page);  in dma_pool_alloc()
430 	spin_unlock_irqrestore(&pool->lock, flags);  in dma_pool_alloc()
432 	*handle = block->dma;  in dma_pool_alloc()
435 		memset(block, 0, pool->size);  in dma_pool_alloc()
442  * dma_pool_free - put block back into dma pool
448  * unless it is first re-allocated.
455 	spin_lock_irqsave(&pool->lock, flags);  in dma_pool_free()
458 		pool->nr_active--;  in dma_pool_free()
460 	spin_unlock_irqrestore(&pool->lock, flags);  in dma_pool_free()
480  * dmam_pool_create - Managed dma_pool_create()
483  * @size: size of the blocks in this pool.
494 				  size_t size, size_t align, size_t allocation)  in dmam_pool_create()  argument
502 	pool = *ptr = dma_pool_create(name, dev, size, align, allocation);  in dmam_pool_create()
513  * dmam_pool_destroy - Managed dma_pool_destroy()
520 	struct device *dev = pool->dev;  in dmam_pool_destroy()